Yes I did stop taking it. It definitely did the trick for me too - my cycles were all over the place, very long, and the cycle I took the Vitex (also took Evening Primrose Oil for 14 days at beginning of cycle) was the cycle I conceived
DS. My cycles had been very long, and that cycle was down to 32 (my usual length now that I am unaffected by any other factors is 28 days)
It's actually very strongly recommended to help cycles get back on track after bcp, I would take it for a cycle and see what happens, you might find that it does its magic after only one cycle and you don't need to keep taking it.